1. Field of the Invention
The present invention relates to a sliding door assembly wherein the sash of the door seals against the door frame.
2. Background of the Prior Art
The main function of a building""s envelope is to prevent water penetration into the interior of a building where such water can cause substantial damage. One problem in any envelope design is the junction between two or more items made from dissimilar materials such as where doors and windows integrate with the main building facade. As the two items are made from different materials, each material thermally expands and contracts at a different rate placing stress on the boundary joint of the two items. Caulks having a high coefficient of expansion and other techniques are used to address this problem. The caulks expand and contract and help modulate the expansion and contraction of the materials to which they are deposited upon.
Operable windows are another problem area in building moisture intrusion. By definition, when a window is open, access is provided into the interior of the building. Therefore, once the window is closed it must provide a moisture barrier for the building. Windows that swing out to open, similar to doors, press up against a peripheral flange on the window frame, which flange has a gasket thereon, which seals the sash of the window against the frame providing the moisture barrier. In the case of an in-swing door, wherein the bottom of the door does not press up against a sealing flange, appropriate rubber sweeps are placed along the bottom of the door in order to block moisture penetration therepast and the threshold is angled outwardly in order to channel any residual moisture back out.
Sliding windows present another problem in dealing with moisture penetration. As the window must slide up and down in a track, the window cannot press against a sealing flange like a swing window. As the window only presses up against one side of its sash, this is the only side where it is possible to have a press seal against the frame. The opposing side, where the sash typically interacts with another sash, which other sash may be fixed or movable, a gasket is provided on one of the sashes in order to provide a barrier between this junction. While such a gasket is not as formidable as a press seal, this junction is constructed such that the upper sash is oriented outwardly relative to the lower sash so that any moisture that challenges this gasket seal must travel upwardly to get to this seal. While it is possible to have storms that have winds that drive rain upwardly, the vertical vector component of such winds are not very large, therefore, the rain acts on the gasket with only a relatively small force, which the gasket handles. Additionally, such storms are very infrequent so that the gasket is not subject to frequent substantial challenges.
The sides of the window wherein the sash rides in a track pose a different problem. As the sash must travel up and down along this track, an airtight seal between sash and frame along the track is not possible. However, the tolerances between the sash and the frame are very tight so that most if not all moisture is stopped at the junction of sash and frame. For any moisture that bypasses this junction, the frames typically have a flanging system that deflects the water and channels the water back to the outside.
The problems associated with moisture barrier protection for horizontal sliding windows and more particularly sliding glass doors is much more challenging. The junction between two closed sashes on a sliding glass door is vertical. Therefore, the gasket that seals the junction between the two sashes is subject to rain any time the wind blows from the appropriate direction during a storm and as the door is at ground level, the lower part of the junction is subject to a rain load almost every shower due to the rain hitting the ground proximate the sash and splashing against the seal. Additionally, the flanging systems used on the windows to deflect moisture that passes the sash-frame contact area cannot be effectively used on the lower part of the door. As people must be able to pass through the door, the lower threshold must be kept to a reasonably short height in order to adequately facilitate walking therethrough. This height restriction is set not only by the desired comfort level of users of the door, but also by the Americans with Disabilities Act which sets upper height restrictions on all new construction sliding doors. Therefore, vertically disposed flanging systems that are commonly found on hung windows, which systems tend to be relatively wide, cannot be effectively deployed on a sliding glass door that has threshold height restrictions and which also requires that the threshold be subject to the forces associated with people walking thereon. Accordingly, moisture barrier systems found on sliding doors tend to be less reliable relative to other door and window moisture barrier systems.
The flanging systems found on current sliding doors tend to have multiple spaced apart flanges in order to accommodate the tracks upon which each sash of the door slides and to act as rain barriers. Such a multiple flange configuration, even though it is relatively low in height, is somewhat uncomfortable to walk across and is difficult to bypass in a wheelchair that must pass across the several flanges.
Additionally, sliding doors tend to be larger than most windows, therefore, they tend to become xe2x80x9cloosexe2x80x9d over time through repeated use. As such doors require tight interfitting between parts in order to provide a strong moisture barrier, such loosening tends to degrade the moisture barrier capabilities of the door.
Therefore, there exists a need in the art for a sliding door system that has moisture barrier capabilities that overcome the above stated problems found in the art. Specifically, such a door must provide a high level of reliability in its moisture barrier properties while maintaining a sufficiently small lower threshold that addresses user comfort and complies with the Americans with Disabilities Act. Such a door must maintain the high level of moisture barrier reliability even if the door becomes loose through normal wear and tear and the passage of time. The threshold found on such a door should be relatively more comfortable to walk across with respect to current sliding door systems and must be relatively easy to bypass in a wheelchair. Ideally, such a door will be of relatively simple design and construction using standard manufacturing techniques to construct and will be relatively easy to use and maintain.
The sliding door assembly of the present invention addresses the aforementioned needs in the art. The sliding door assembly provides a a moisture barrier that has a high level of reliability. The sliding door assembly uses a small lower threshold that addresses user comfort and complies with the Americans with Disabilities Act. The flanging system on the threshold is relatively more comfortable to walk across with respect to current sliding door systems and is relatively easy to bypass in a wheelchair. The sliding door assembly maintains the high level of moisture barrier reliability even after the door becomes loose through normal wear and tear and the passage of time. The sliding door assembly is of relatively simple design and construction using standard manufacturing techniques and is relatively easy to use and maintain.
The sliding door assembly of the present invention is comprised of a frame that has a top leg and a bottom leg joined by a first side leg and a second side leg such that a first channel is located along a portion of the top leg, the first channel having a curved portion. A pocket extends along a portion of the top leg, the first side, a portion of the bottom leg, and between the top leg and the bottom leg, along a mullion. A compression gasket is located within the pocket, the gasket being continuous in order to form a closed loop. A first jamb extends along the first side leg, the first jamb having a first angled face, a first opening located on the first angled face, and a first inner wall. A first sash has a second jamb with a second angled face located along a first side edge of the first sash. The first sash also has an inner face and an outer face. A post, having a roller, is attached to a top edge of the first sash and passes through the first channel such that the roller rests on the top leg in order to gravitationally suspend the first sash therefrom and permit the first sash to slide along the top leg. A first dog is rotatably attached to the first side edge of the first sash. A third jamb extends along the mullion, the third jamb having a third angled face, a second opening located on the third angled face, and a second inner wall. The first sash has a fourth jamb with a fourth angled face located along a second side edge of the first sash opposite the first side edge. A second dog is also rotatably attached to the second side edge of the first sash. A handle is attached to the first sash and is operatively connected to the first dog and the second for rotation of the two dogs. A second sash is fixedly attached to the frame and to the mullion. The first sash is slidable between an open position and a closed position wherein when the first sash is in a closed position, the first angled face faces the second angled face in close proximity and the third angled face faces the fourth angled-face in close proximity. The handle is activated in order to rotate the first dog and the second dog so that the first dog passes through the first opening and acts on the first inner wall and the second dog passes through the second opening and acts on the second inner wall so that the inner face of the first sash presses against the gasket in order to achieve an airtight seal between the first sash and the gasket. The bottom leg has a second channel and the first sash has a pin that passes through the second channel, the pin helping to stabilize the first sash during first sash movement. The handle can be latched, which may be an over-center latch, in order to maintain the dogs in the acting relationship with their respective inner walls. Ramped detents located on the top leg help hold the first sash in a fully closed or a fully open position.